Peptide-type immunizing agents generally belong to a class of polypeptide hormones, most of which are drugs, such as thymic peptide, thymic pentapeptide, immunoglobulin, gamma globulin, human serum albumin, interferon, tumor necrosis factor, interleukin I, interleukin II, interleukin III and the like. These peptide-type immunizing agents are all isolated and extracted from glands, tissues or blood of an animal. These polypeptide drugs are mostly an injection, and can only be applied on certain patients. During the use, a response such as rejection, allergy and side effect tends to occur. It is necessary to be cautious and under physician's strict supervision for the application.